Hey gentlemen,
thanks for the vauable inputs. I did a research on this in the past weeks and some things are not exactly correct for a FO hired through McGinley. In this case you only pay the social contributions in Germany whereas all taxes are paid in Ireland. Therefore: No Soli, no Church tax nada... Thats a good news.
The bad news is that the expenses CANNOT be used to lower the social contributions. You get the money you earn from RYR. Lets say 70k per year. Thats your gross salary + the employers contribution. You need to deduct 17,87% in order to get your gross salary for the tax purpose. That's 57,5k. Thats your gross salary. From this you need to pay 20,52% as an employee's contribution + the Irish income taxes. The only thing you can use your expenses for are the Irish taxes. So even if you have plenty of expenses and will pay zero tax you will never get more than 45,7k net. That is a maximum 65% retention rate. You will never get more out of it unless you opt out from the state health insurance system - which you actually can't, because you would have to earn more than 59,4k gross salary (current threshold for 2018 - goes up by 2-3% every year). But even if you slightly surpass the threshold an will have the option to go for the private health insurance, it brings you some savings in short run but in the long run it is always pretty difficult to get back to the state system. If you are German or wish to stay in Germany in the long term, you'll be surprised that on the contrary to the state system you will have to pay for the health insurance of your kids (free in the state system) and that your mothly payments will go up every year. One day, when you retire you'll have to pay up to 1000 EUR per month just for your private health insurance without any possibility to do something about it. Some people even pay more on health insurance than they get from the state pension system. Anyway... Opting out from the state health insurance brings the theoretical maximum retention for Germany to 76,6% - but you need to pay the health insurance on you own. That means 8 - 9k per year of additional income, 3,5k of which you pay for the private health insurance. Your total net saving is therefore 5,5k p.a. Which is not bad, but it gets much lower when you get older / have kids.
Interesting article on this: ht tps://oconnorandassociates.freshdesk.com/support/solutions/articles/25000013667-are-expenses-allowable-in-germany-to-reduce-the-amount-of-social-insurance-i-pay-